Balancing method for color wheel

Abstract

A color wheel is provided for use in the illumination system of a projector. The color wheel includes a rotor and a motor for rotating the rotor, the rotor includes a ring shaped translucent area formed by color filter segments, the translucent area being adapted to continuously extend into a light path as the rotor is rotated, the rotor in a first plane perpendicular to the axis of rotation further includes first means for balancing, the rotor in a second plane perpendicular to the axis of rotation further includes second means for balancing, wherein the first and the second plane are spaced apart. Due to the dual plane balancing means, the color wheel is better balanced.

1. A color wheel comprising in combination
 a rotor and 
 a motor for rotating the rotor; 
 the rotor comprising a ring shaped translucent area formed by color filter segments, 
 the translucent area being adapted to continuously extend into a light path as the rotor is rotated; 
 the rotor in a first plane perpendicular to the axis of rotation further comprising first means for balancing, 
 the rotor further comprising an additional rotational symmetric body that includes a second plane perpendicular to the axis of rotation further comprising second means for balancing; 
 wherein the first and the second planes are spaced apart by a distance D with
     D=k*R   I    
 
 wherein R I  is the inertia radius of the rotor and k is a factor of at least 0.25. 
 
     
     
       2. A color wheel according to  claim 1  wherein k is at maximum 10. 
     
     
       3. A color wheel according to  claim 1  wherein k substantially equals 0.5. 
     
     
       4. A color wheel comprising in combination
 a rotor and 
 a motor for rotating the rotor; 
 the rotor comprising a ring shaped translucent area formed by color filter segments, 
 the translucent area being adapted to continuously extend into a light path as the rotor is rotated; 
 the rotor in a first plane perpendicular to the axis of rotation further comprising first means for balancing, 
 the rotor further comprising an additional rotational symmetric body that includes a second plane perpendicular to the axis of rotation further comprising second means for balancing; 
 wherein the first plane and the second plane are spaced apart; 
 wherein the rotational symmetric body has an axial length of at least D al =D=k*R I    
 wherein R I  is the inertia radius of the rotor and k is a factor of at least 0.25. 
 
     
     
       5. A color wheel comprising in combination
 a rotor; and 
 a motor for rotating the rotor; 
 the rotor comprising a ring shaped translucent area formed by color filter segments, 
 the translucent area being adapted to continuously extend into a light path as the rotor is rotated; 
 the rotor in a first plane perpendicular to the axis of rotation further comprising first means for balancing, 
 the rotor in a second plane perpendicular to the axis of rotation further comprising second means for balancing; and 
 wherein the ring shaped translucent area is positioned between the first and the second plane; 
 wherein the first and second planes are spaced apart by a distance D with
     D=k*R   I    
 
 wherein R I  is the inertia radius of the rotor and k is a factor of at least 0.25. 
 
     
     
       6. A color wheel according to  claim 5  wherein k is at maximum 10. 
     
     
       7. A color wheel according to  claim 5  wherein k substantially equals 0.5. 
     
     
       8. A color wheel comprising in combination
 a rotor and 
 a motor for rotating the rotor; 
 the rotor comprising a ring shaped translucent area formed by color filter segments, 
 the translucent area being adapted to continuously extend into a light path as the rotor is rotated; 
 the rotor in a first plane perpendicular to the axis of rotation further comprising first means for balancing, 
 the rotor further comprising an additional rotational symmetric body that includes a second plane perpendicular to the axis of rotation further comprising second means for balancing; 
 wherein the first and second planes are spaced apart; 
 wherein the second means for balancing is configured for adding material and for removing material. 
 
     
     
       9. A color wheel comprising in combination
 a rotor; and 
 a motor for rotating the rotor; 
 the rotor comprising a ring shaped translucent area formed by color filter segments, 
 the translucent area being adapted to continuously extend into a light path as the rotor is rotated; 
 the rotor in a first plane perpendicular to the axis of rotation further comprising first means for balancing, 
 the rotor in a second plane perpendicular to the axis of rotation further comprising second means for balancing; and 
 wherein the ring shaped translucent area is positioned between the first and the second plane; 
 wherein the second means for balancing is configured for adding material and for removing material.